Fermi-liquid-to-polaron crossover. ii. double exchange and the physics of colossal magnetoresistance

TLDR: The dynamical mean-field method is used to study a model of electrons Jahn-Teller coupled to localized classical oscillators and ferromagnetically coupled to core spins that contains the essential physics of theossal magnetoresistance of manganites.

Abstract: We use the dynamical mean-field method to study a model of electrons Jahn-Teller coupled to localized classical oscillators and ferromagnetically coupled to {open_quote}{open_quote}core spins.{close_quote}{close_quote} The model, we argue, contains the essential physics of the {open_quote}{open_quote}colossal magnetoresistance{close_quote}{close_quote} manganites Re{sub 1{minus}{ital x}}{ital A}{sub {ital x}}MnO{sub 3}. We determine the different regimes of the model and present results for the temperature and frequency dependence of the conductivity, the electron spectral function, and the root-mean-square lattice parameter fluctuations. We compare our results to data and give a qualitative discussion of important physics not included in the calculation. Extensive use is made of results from a companion paper [Phys. Rev. B {bold 54}, 5389 (1996)]. {copyright} {ital 1996 The American Physical Society.}